[Sync] Clean up ProfileSyncService observer events

chrome/browser/sync/glue/sync_backend_host_impl.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_IMPL_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_IMPL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 161 matching lines @@
   // |sync_context_proxy| points to an object owned by the SyncManager.
   // Ownership is not transferred, but we can obtain our own copy of the object
   // using its Clone() method.
   virtual void HandleInitializationSuccessOnFrontendLoop(
       const syncer::WeakHandle<syncer::JsBackend> js_backend,
       const syncer::WeakHandle<syncer::DataTypeDebugInfoListener>
           debug_info_listener,
       syncer::SyncContextProxy* sync_context_proxy,
       const std::string& cache_guid);
 
-  // Downloading of control types failed and will be retried. Invokes the
-  // frontend's sync configure retry method.
-  void HandleControlTypesDownloadRetry();
-
   // Forwards a ProtocolEvent to the frontend.  Will not be called unless a
   // call to SetForwardProtocolEvents() explicitly requested that we start
   // forwarding these events.
   void HandleProtocolEventOnFrontendLoop(syncer::ProtocolEvent* event);
 
   // Forwards a directory commit counter update to the frontend loop.  Will not
   // be called unless a call to EnableDirectoryTypeDebugInfoForwarding()
   // explicitly requested that we start forwarding these events.
   void HandleDirectoryCommitCountersUpdatedOnFrontendLoop(
       syncer::ModelType type,
@@ skipping 169 matching lines @@
 
   base::WeakPtrFactory<SyncBackendHostImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHostImpl);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_IMPL_H_